The Constitution Court on Wednesday rejected a challenge to the government's rice pledging scheme, saying the petition is outside its field of jursdiction.

Moreover, the petitioners were not the party whose rights and liberties had allegedly been violated by the scheme, the court ruled.

Court spokesman Pimol Thampithakpong said the ruling was unanimous, with a vote of 9-0.

The petition, which sought a court injunction halting the scheme, was filed by academics and students from Thammasat University and the National Institute of Development Administration (Nida) led by Adis Israngkura na Ayutthaya, dean of Nida's School of Development Economics.

The petition said that pledging principle required that pledged price should be lower than the market price, to allow farmers to redeem their rice when the price goes up.  Under the rice pledging scheme, the government intentionally fixed a much higher pledged price than the market price, with no intention of  farmers ever redeeming the rice.

In doing so, the government was becoming the largest rice trader in the country, in comnpetition with the private sector.  It was a monopoly and therefore destroyed the trade system, affecting the rice production system and distorting market mechanisms, the petition argued.

Mr Pimol said the court had performed its duty impartiality and without political pressure.  If the petitioners wanted to petition another agency, they should first find out if it had the power to take it up for consideration, he added.

In this case the Consitution Court decided it does not have the power under Section 212 of the constitution to take the petition for consideration.  The petitioners were not parties whose rights and liberties had been violated by the implementation of the scheme, Mr Pimol said.

Earlier today, Prime Minister Yingluck Shinawatra said she would order the Commerce Ministry to hold a press conference to give details on sales of eight million tons of pledged rice in government-to-government (G-to-G) deals, including the countries which signed a memorandum of understanding, the opening of letters of credit  and deliveries of the rice.

Ms Yingluck said some information in the G-to-G may be confidential, but the government would make as much as possible public to ensure a better understanding.

Asked about the alleged corruption in the implementation of the scheme, the prime minister said Deputy Prime Minister Chalerm Yubamrung had been assigned to investigate.

Asked if ministers in the economic team agreed with the scheme, she said they should because it is one of the government's policies.